Simulink does not support code generation issue.

I am trying to replace a 3-point summing block with a function block.

First I started by placing the code inside the function block:

function y = fcn(u)

sys1 = tf(0.5,[1 0 0 4]);
sys2 = tf([3 0.5],[1 0 15]);
sys3 = tf(1,[1 1]);

y = sys1 + sys2 + sys3;

However I was greeted with an error saying that Simulink does not support code generation.

"The 'tf' class does not support code generation."

I then came across a similar problem here: https://nl.mathworks.com/matlabcentral/answers/74770-is-there-any-way-to-disable-code-generation-in-simulink

I am trying to implement an extrinsic function or'wrapper function` with some difficulty. I created a new script called myWrapper.m, containing the same code:

function y = myWrapper(u)

sys1 = tf(0.5,[1 0 0 0 4]);
sys2 = tf([3 5],[1 0 15]);
sys3 = tf(1,[1 1]);

y = sys1 + sys2 + sys3;

and the MATLAB Function edited to:

      function y1 = fcn(u1)

      y1 = myWrapper(u1);

The error persists.

I somehow want to access `myWrapper.m` file from the MATLAB Function block. Any pointers on how this should be done? Following the previous link given and the [official docs][2] I am ending up with something like this in my MATLAB Function block:

function y = fcn(u)coder.extrinsic('myWrapper')

y = myWrapper(u);

The last code above is syntactically incorrect and I am at a loss on how it should be done. MATLAB automaticaly corrects the above code to:

function y = fcn(u,coder,extrinsic, myWrapper )

y = myWrapper(u);

which is not what I want.

Any tips on how this could be done would be appreciated.